P23D8Cylinder 2 Fuel Heater Performance
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- P23D8 concerns how well the cylinder 2 heater works, not its wiring. According to Bosch, the Flexstart heated rail warms pure ethanol fuel at rates of as much as 30 °C a second, so a system of this kind knows roughly how quickly each heating point ought to warm up. If cylinder 2 rises clearly slower than expected, draws less current than its neighbours or never reaches its target temperature, the performance code follows. Typical reasons are an aged element, scale or varnish on the heated surface and a corroded contact that drops voltage under load. No manufacturer documents P23D8 or its thresholds publicly; CARB expects functional checks of heated fuel preparation. The driver mostly notices a rough first minute on cold ethanol. Electrical faults on this path are P23D5 to P23D7.
- What you may notice
- Cylinder 2 runs rough for about a minute after a cold ethanol start
- Longer cranking below freezing
- Engine warning lamp, depending on manufacturer
- Likely causes
- LikelyCylinder 2 heater element with reduced output
- PossibleVarnish or scale on the heated surface at cylinder 2
- PossibleCorroded contact dropping voltage under heater load
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €80 – €600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.